League of Women Voters of Wilmette. Stormwater Study, 2014

Transcription

1 League of Women Voters of Wilmette Stormwater Study, 2014

2 Objectives To review current status of stormwater management in Wilmette To understand outside entities whose regulations impact what the Village can or cannot do To review accepted and emerging best practices in stormwater management To evaluate Wilmette actions in the context of such practices If there are discrepancies, to determine what needs to happen to move Wilmette towards better practices To determine what the League s appropriate role is in this process

3 A community-wide problem requires a community-wide response from education => implementation

4 Introduction Stormwater flooding from intense rain events: is expensive to clean up (time and money) depresses property values devalues reputation of village as a place to live increases insurance rates or causes loss of coverage degrades quality of waterways affects public safety (electrical wires, impedes traffic) disrupts business

5 Stormwater Is Often Highly Polluted - How we dispose of it matters! The first inch of rain creates the most polluted stormwater, especially after dry spells Largest contributor: transportation Oil & antifreeze droppings from cars, busses and trucks Particulate material from exhaust and brake lining Debris on roadways Sand & salt Second largest: residential and commercial Lawn chemicals Animal waste Coal tar treatments on roadways and driveways Soaps from car washing Discharges of petrochemicals

6 Why is stormwater pollution an issue? Nitrogen and phosphorus from sewage plants, urban stormwater runoff and agricultural operations cause algae blooms Chokes out other aquatic life Robs water of oxygen fish need to survive Impairs beaches & recreational activities Affects drinking water supplies Examples Emergence of the dead zone in Gulf of Mexico An area the size of Connecticut Algal growth has driven oxygen levels at seafloor so low virtually nothing can live there. Lake Erie - algae blooms have returned in force Lake Michigan seeing effects on drinking water, increased bacterial counts and beach closures

7 Stormwater Flooding in Wilmette, April 2013

8 Understanding Flooding There are 3 types of flooding that commonly affect urban residents: Water Backup from floor drains, bathtubs, and sinks Water Seepage through cracks in floors or foundation walls Overland Flooding across yards or into basements

9 Terminology inflow stormwater that enters sanitary and stormwater pipes through direct connections (downspouts, sump pumps, foundation drains, window wells) infiltration stormwater as groundwater that enters sewers through cracks or leaks in pipes (property owners & municipal) and municipal street basins overland or surface flooding stormwater that flows over land and exceeds the capacity of drainage systems, accumulating in low-lying areas overbank flooding stormwater that overflows rivers & streams combined sewer overflow combined sewers full, contents spill over into waterways

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11 Runoff with Respect to Land Coverage Runoff volume after 1 rain in cubic feet of water 1 acre pasture land Pervious 1 acre parking lot Impervious 218 3,450 Shifts in land use have resulted in nearly a 16 time increase in runoff Moreover, now much of our stormwater ends up in the Mississippi and thence to the Gulf of Mexico vs being retained within our community or treated and directed to the Lake rain is not recharging water table here and Lake water is ending up in the Gulf. Natural Resource Defense Council Figures

12 Looking East from West Wilmette 1926 (Wilmette Ave on the left, Glenview Road on the right)

13 Increase in runoff as area of permeable surfaces decreases Extra runoff goes into the same 12 pipe in the middle of the street. Renderings Courtesy of Debra Shore

14 Terminology Gray infrastructure: pipes, deep tunnels, street basins, large detention storage areas Green infrastructure: rain gardens, bioswales, retention basins, porous pavers, roof gardens Rendering Courtesy of Conservation Design Forum

15 Ways to Increase Capacity to Manage Stormwater During Intense Storms Increase size/number of pipes and treatment plants in system Slow flow of water and release it for processing over longer period of time (detention) Choose not to move water from where it falls (retention) Combine approaches Or Or Or

16 Stormwater Disposal Challenges Common problems throughout Wilmette Many municipal pipes & catch basins are old, undersized, leaky or otherwise need repair Property owners may have cross connections and/or inadequate property barriers* Many parts of Wilmette were built before stormwater flooding was an issue Enforcing compliance is complicated Some older property owners grandfathered Recent Clean Water Act rules only apply to new construction Fines, tickets, and court actions for violations apply in some but not all cases *Hundreds of homes have drain tiles without sump pumps that during storms dispose of stormwater into the sewer or stormwater systems.

17 Development of Sewer System for Wilmette 1872 Village incorporated. All sewage => Lake Michigan Village smaller (Ridge Rd to the Lake) 1914 All sewage => North Shore Channel 1924 Annexed Gross Point (became W Wilmette), but it was then mostly farms E of Ridge, combined sewers => to MWRD for tx W of Ridge sanitary sewers => MWRD for tx stormwater => NBCR no tx 1986 dye tested whole village looking for cross connections 1987 Ordinance requiring downspouts to be disconnected relief sewers (Greenleaf Avenue) street berms and inlet restrictors second stormwater outfall Backup generator at stormwater pump station sewer cleaning, televising, lining, rehabilitation sewer main repairs Current work in West Park

18 Waste & Stormwater Disposal East of Ridge Rd All managed in combined sewers => via pipes to MRWD (Howard St.); Theoretically all treated all treated water is ultimately discharged to the Gulf of Mexico BUT in intense storms Some flows into North Shore Channel (this happens simply as a function of hydraulic pressure from the volume of stormwater) Some stormwater is retained in street detention areas - then sent to MWRD after storm as street drains accept water (restrictors in storm basins released) If there is too much water, combined overflow goes in the lake via opened locks (MWRD controls the locks)

19 Waste & Stormwater Disposal West of Ridge Rd All separate sanitary & stormwater sewers Ridge Rd West to Romona Rd Sewage => Princeton Pl station => to MWRD & treated Stormwater => Harms Rd station => untreated => North Branch of the Chicago River Romona Rd West to Harms Rd Sewage => Harms Rd Station => to MWRD & treated Stormwater => Harms Rd Station => untreated => North Branch of the Chicago River Normal rainfall: no flooding issues but pollution in waterways Intense rainfall: some neighborhoods experience sewage and/or stormwater backups. Also pollution in waterways

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22 To Address the Problem, the Source Matters Most pipes last yrs; many Wilmette pipes & lateral connections are older (E ~60-80 yrs W ~40-60 yrs) Older pipes susceptible to cracks & breaks Most private property pipes: never evaluated Many property owners: unaware of problem Continuously flowing sump pump puts >7,000 g => sewer in 24-hr period (= daily avg flow for 26 homes) Contributes to overload of municipal pipes Burden to MWRD treatment plants

23 Stormwater Discharge Point All of Wilmette W of Ridge Rd Few current volume limits or requirement for testing or management quality of water discharged. Wilmette s discharge blends with those from northern communities and is sent on to southern communities and ultimately to the Gulf of Mexico.

24 Research has shown that in as much as 70% of defect-related inflow & infiltration of stormwater in sanitary pipes in villages like Wilmette the source is from private connections. sanitary sewer line is filled with extraneous stormwater Capacity of sewer is exceeded Sewers become surcharged => => => Sewage in basements

25 Types of Problems Identified in West Wilmette Evaluations Made by Consultants in 1988 Infrastructure issues Manhole covers in disrepair (996) Need for detention area at Princeton Place Specific places with undersized pipes, defective walls in street structures, grading issues Property owners issues Downspouts directly connected to sanitary sewers (3,189) Stormwater sump pumps connected to sewers (1,909) Other cross connections (66) Foundation drains contributing groundwater to sewer load (2648) Outcome Recommended repairs were made on the Village side Property owners were given notice about needed repairs, given a timeframe for remediation, fined if remained non-compliant. Most addressed, the exception being foundation drain issues.

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28 Survey Results: Cautionary Note Survey completion rates are low because property owners: o o o Fear reporting will adversely affect property value Underreport stormwater issues because policies only cover sewage back ups Cultural norms preclude airing private problems

29 Ordinances: Cook County Cook County Watershed Stormwater Ordinance Ordinance will go into effect 4/1/2014 Promotes the integration of green infrastructure into new development and redevelopment projects of >1 acre Reduces amount of runoff entering the sewer systems Not intended to solve current water pollution and flooding problems, only to prevent making situation worse

30 Challenges in Addressing Stormwater Flooding in Wilmette Infrastructure o Age of sewer system o Majority of village developed before stormwater was an issue Complexity of incompatible systems as Wilmette grew Scant funds for analysis & remediation Imperfect understanding of problem and solutions o Property owners o Municipal oversight o Regional oversight

31 Best Practices: General Principles Create Stormwater Master Plan with long-term and annual goals including provisions to: Modernize stormwater infrastructure Separate stormwater & sewer collection whenever possible Line salvageable pipes; replace broken & undersized pipes Develop detention regions Implement best practices for preventative maintenance Measure progress and inform public Reduce need for costly upgrades to gray infrastructure by: Supplementing system using green infrastructure practices to slow the flow of stormwater and reduce the volume Increase effective capacity by shifting time when water is processed

32 Best Practices: General Principles (Cont d) Reduce inflow & infiltration into sewer system Test for cross connections in underground pipes Monitor for unnecessary connection from downspouts & sump pumps Enforce rules for eliminating identified problems Increase pervious land within community Through land-use rules for permeability o By tightening criteria for zoning ordinances & variations o Applying rules to commercial, municipal, & residential properties Through incentives to create green spaces Foster best practices among property owners Engage property owners in campaign to reduce volume of stormwater going into municipal sewers

33 Best Practices: General Principles (Cont d) Establish rules for stormwater pollution control Introduce stormwater-sensitive rules for lawn care, driveway upkeep, car maintenance practices Foster the attitude that stormwater is a resource rather than something to dispose of (eg, control & manage close to the source) Coordinate efforts with adjacent/overlapping jurisdictions in same watersheds

34 Best Practices: General Principles (Cont d) Involve public through efforts to educate, identify problems & solutions, and to prioritize Lastly, to drive data-driven changes and monitor effectiveness Monitor stormwater runoff for water quality From the site of discharge For a number of water quality indices On a regular schedule Measure volumes discharged downstream - more than by estimating pump volumes and hours of use

35 Rain Ready Approaches for Managing Stormwater Flooding Center for Neighborhood Technology 1. Begin by assessing properties that are most at risk 2. Coordinate solutions by both properties and neighborhoods 3. Include contingent public right of way in assessments of problems 4. Introduce regulations and ordinances that address biggest contributions to stormwater runoff (eg, houses built in the wrong place, large parking lots without provisions for detention) 5. Reward property owners for good practices; create fair fee systems for stormwater fees 6. Promote coverage of flood insurance through National Flood Insurance Program certification and Community Rating system

36 Specific Best Practice Actions: Village Televize network of pipes for breaks & clogs * Clean sanitary & stormwater pipes * Clean & repair broken manholes * Line pipes (when appropriate); replace broken pipes * Regular street sweeping * Clear basins * Seek National Flood Insurance Program (NFIP) certification * and Community Rating System (CRS) to lower flood insurance fees Review Village ordinances for site development, sewer connections, floodplain policies & stormwater management Coordinate efforts with other municipalities Pursue internal and external funding sources Establish a Wilmette Stormwater Task Force *These are happening in Wilmette to various extents

37 Specific Best Practice Actions* Property Owners Televize network of pipes (laterals) for breaks and clogs Line pipes (when appropriate) Replace broken pipes Install overhead sewer systems Disconnect downspouts & direct water to pervious places on property Install rain gardens, bioswales, dry creeks, detention areas, porous driveways Mulch grass & leaves and retain vs => Village collection Minimize use of household water during intense storm events; do not drive through deep water *These practices are happening in Wilmette on a patchwork, nonsystematic basis

38 Best Practices - Summary for Municipalities Ultimately, the goal for any village is to achieve effective stormwater control that: is fiscally responsible with respect to: municipal costs/property taxes impact on property values cost of damage remediation minimizes environmental impact protects public safety is sustainable for long term

39 Best Practices: Pollution Reduction Street sweeping (vacuum grit, keep leaves & trash out of drains) Add ordinances for toxic-free, low-impact landscaping practices Require downspout disconnects (utilize pop up discharge systems) Introduce sediment control areas (detention/retention areas) Clean catch basins frequently Use parkland for retention basins that help cleanse stormwater and provide irrigation options for parks. Introduce municipal bioswales and other green infrastructure and incentivize residential and business installations.

40 Peter Senge in The Fifth Discipline tells us Today s problems often stem from yesterday s solutions In the context of stormwater management Deferring capital improvements now, leads to more costly repairs in the long run and greater costs to residents from repetitive storm damage Choosing options easiest for Wilmette now may adversely affect downstream communities later Failing to work collaboratively with neighboring communities now may adversely affect our community in years to come What we do in the short-term may affect long-term effects for generations to come Wilmette needs to do this right